Electrical cut-out



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April .22 1924.

ELECTRICAL cT-ouT Filed oct. 5. 1920 2 sheets-snag: 1

llllllll Patented Apr. 22, 1924.

UNITED sTATEs 1,490,925 PATENT ori-"ICE,

WILLIAM HENRY ILLINGWORTH, F HALIFAX, ENGLAND.

ELECTRICAL CUT-DUT.

Application tlled October 5, 1920. .Serial No. 414,918.

To allwhom it may concern.' l

Be it known that I, WiLLrAM HENRY Ii.- LiNowonm, a subject of the King of Great Britain, residing at 1 Ruskin Terrace, Leei thicker wire, or onehaving a higher fusing point is substituted for the correct wire, also to do away with arcing and avoid asudden surge of current on a dead short circuit.

According to this invention a column of mercury restricted at some portion of its length forms an electrical connection between two contacts but parts at the restricted sortion when the current reaches a preetermiued amperage. The gas generated bly vaporization of the mercury escapes to t e atmosphere through one or more apertures in a chamber containing a plunger and the mercury that has been thrown out of the passage above' the restricted ortion collects in the form of a small globu e in a cup, or basin, at the top of the passage. To remake the contact the plunger is depressed against the actionA of a sfpring and as soon as it enters the basin it orces the lmercury back into the passage.

In the accompanying drawings Figure 1 is a section of a cut-out constructed in accordance with this invention.-

Figure 2 is an elevation of a cap or cover for t e same.

F' re 3 is asimilar view to Figure 1 showing a modied construction of cutout. Figure 4 is a view of a distribution board with the-cover removed.

Figure s is a front view of the im portion of a porcelain insulating holder.

Figure 6 is an end view and Figure? a` l plan cfa complete unit, and

Fi re 8 is a transverse" section of the ineulating holder.

Fi n e is a wenn showing s slightly m ed construction of unit and pump.

Referring to Figures A1 and 2 the column a of mercury is contained in a tubeA of any suitable known insulatin material, or composition, that is prefera l of a. refractory nature. The passage for t e column of meris shown restricted at a, the diameter an length of the passage and the distance at whic it is placed from the top of the tube determining the amperage at which the column will part. The tube is formed with a collar a1 to form an abutment 'a' for two metal thimbles, or fittings B, B1, which carry thevtop and bottom contacts C, C1, respectively. Each fttin is made with a socket b adapted to lit ti tly upon its respective end o the tube an to be pressed up tov the collar. The contact C is constructed from cop er and made in the form of a cup vor basin with a short length of tube c to enter a hole in the top of the insulating tube, until it meets the restricted passage a, the diam eter of the hole in the copper tube being slightly lar er than the latter. Projectin from one si e of the basin is an arm o1 whic pro]ects through the side of the fitting and carries a binding screw c2, or anfv other suitable terminal. The portion o the fitting labove the basin constitutes a cylindrica chamber b1 havin one or more vent apertures b and on t e top of this chamber, a'

cap b is detachably secured. This cap is formed with a -central aperture bf for the assage of a sleeve D in which a plu r E is free to work and is made of suitable iameter to enter the cu The sleeve is formed with a collar d to t the chamber and such collar is formed with one or more nicks d* to allow air to pass by it when the sleeve is de ressed. The sleeve has a bevelled edge d* a apted to bear against a seating b when the sleeve is depressed and such sleeve is normall retained in its outer position by a sprin The plunger is provided wit a radia in .e which projects through a slot d* in tltie sleeve and is retained in its outer position by a splin e1 interposed between the sleeve and a o e. When the plun r is depressed it first lowers the bevelled e ge of the sleeve onto its seating so forming a closure for preventing escape of mercury, the plunger then enters the cup and returns the globule of mercury which has been thrown out of the tube by the parting of the column, back into the tube and so remakes the column and contact] The.- lower contact C comprises a copxper rod which lits for a portion of its' lengt a passage ofenlarged diameter in the insulating tube and may be formed at its lower end with a head ca which lits tightly into a recess formed in the metal fitting B1. The rod is reduced in diameter at c* to form an annular cavity a3 for the passage of mercury and so ensure good surface contact. In the construction shown in Fi ure 3 the metal ttings IBB1 are 'dispens with, the Whole of the body portion Bx being constructed from one piece of mouldable insulating material with the upper contact embedded in it. In a plying the invention to a distribution boar which may for example be used in connection with an electric lighting circuit, the head of each lower contact is formed with a roove c? to receive a bus bar c (Fig. g which is clamped to it by a cap c havinga similar groove c, and connected to the lower portion of the metal ittin or insulat' tube by screws c. Any ot er suitably s aped bus bar ma be used in place of a round one.

In theV istribution board shown in Figure 4,

each tube or cartridge A is clamped betwen two porcelain, or other insulating holders F,

F1, by bolts f and milled nuts f1. The bolts f secure the rear portions of the holders to and 8 for the the casing and the milled nuts f* can be actuated to perform the clampin operations,v

or be removed to enable the j ntl lltion F to be taken off without disturbing t e rear portion. The front portion can be marked withthe particular circuit thatthat particular cut-out controls, it also serves to cover the metallic, or live'partof the cartridge.

Each portion is grooved atf* Figures 5, 6 passage of the bus bar c' and the lower end of the front portion is formed with a tongue f' to cover the lower end of the cartridge. Exten along the top 4of the rear portion is a rib with an opening f' for the passage of a wire c to the terminal c and behind such rib is a channel 'f' in which the various wires lie. cu indicates a main cable one of which 'is connected to each bus bar, c'. In the `form shown in Figure 4 the two sections of the casl which grip thel bus bar are shown as plrlbg vided with lateral lugs which are connected together so that the fastenin screws orconnectin are above the p ane of the bottomotecase.`

Y In the modification shown' in Fig; v9 the ump is placed at the front of the unit beow the restricted passage a. This pumlp is 1s so arran that ,when the plunger ressexed vapour orsuch pasdep it forces the merc air out 'of the p -a and sage with mercury w 'ch' alsoows into the chamber b1, the return stroke of the langer sucking the mercury back through e passage a until it occupies its normal position therein, leaving suicient mercury at the top of the tube to make contactwith the top contact C. When the pump is plaoedbelow thev .plunger E by a spring e7 bearing against a collar es that is' loosely mounted on the plungerv and against a collar e that is ri 'd therewith.l The spring e normally retains the plunger at the outer end of its stroke and a knob el" on the outer end of the plunger e limits the amount of its inward traverse.

The apparatus described may be used in conjunction with switches,. wall plugs, or other small electrical apparatus requiring protection by fuses. It may be enclosed in a casing of lporcelain with anironclad casing outside and the knob of the plunger projecting outside the casing. 'It can also be used for house work to protect supply companies mains, orfor any other pu where fuses are required at theresent time. The amperage can be increase by arrangingV the columns in parallel, or by altering the position, diameter and length of the restricted passage, or it can be reduced b altering the position, diameter and length1 of restricted passage' in a single column to as low as .5' of an am re. Its action is so instantaneous that it 1s impossible to have a fire.

1. In an electrical cut-out, a tubeV of in-4 sulating material having Ja passage for a column of mercury, the said passage .bei

restricted.at some intermediate portion o 'situated at the top of the passage, a chamber s urmounting said'cup, and apertured to 1 the atmosphere, a-plunger mounted in the chamber and ada ted to enter the cup, a contact situated in t e cup 'and having a tubular extension adapted to enter the passage in the tube and an arm branching through the side ofthe latter,-a contact closing-the botlll tom of the tube 'and having its inner end reduced-in diameter to form an annular passage for mercury.

2. In an electrical cut-out, a tube of insulating material' having a 'passage fora column of mercury, `the said passage being restricted at some intermediate portion of its length and having its upper aperture suf-- cientl siall'toh prevent`mcury owing in an fiingte e ygravity a chamber situated allidg the p and apertured 'to the atmosphere,.a lid stach# i ly connected with the chamber, a. sleeve 7 f Ato-prevent mercury ilowing in .andl

and the bottom of the chamb'er which constitutes a seatin for said sleeve, a vplunger slidably moun in the sleeve and connected therewith, through a pin and slot connection, a, spring for normally retaining the plunger in its retracted position, acup sha contact situated at the to of the tube with an arm projecting outsi e the tube, a contact closing the` bottom of the tube and having its inner end reduced in diameter to form an 'annular passage for mercury, and means for connecting conductors with said contacts.

. 3. In an electrical cut-out, a tubeof insulating material having a passage for a column of mercury, the said bein having its upp'er .aperture sumcien small the passage b gravity, twocontacts communicating wit said passage, a plunger for forcslidably mounted in the'lid and having a ing mercury into the latter, an i flange adapted to' fit the bore of the chamo d ber, a spring interposed between the flange part adapted to enclose the tube and contacts y' and leavel the plunger exposed for operating pirpees, the ower end of the front portion ingv formed witha tongue and the lower end of the back portion with .`a reces to receive same, the u per end of the back portion being -1 at the back and continued upwardly in the form of a rib which projectsabove the top'of the back portion and is recessed transversely, the front portion ofthe` holder having a plain surface to 'act as a tablet which can be marked with the,l particular circuit that the cutout controls .means for clamping the holder to a base an means for clamping the tube between the two portions of the holder in such manner that the front rtion can be removed without affecting e connection which connects therear portion to the base.

I'n testimony whereof I ax i 'Humm' Imm.

er comprising a front part and a bac il my signature. 

